I have a child in year 6. He's going to go back. The measures in his school are he is in a bubble of 6, same 6 and same teacher through June. He goes back part time 2.5 days a week, so that the other quarters of 6 are split between classrooms and half's of the week, 24 of 31 children are returning. The bubbles stay together all day for class, lunch, own bathroom, own drop off and collection points and times. Anyone with symptoms and the school will close. Being year 6 they are expected to follow social distancing rules whilst at School (reception and year 1 won't be following those same rules).
The main reasons for us was purely to get he social/friends again prior to the next long break through August and the transition into secondary school. The days going back tie in with the days I'm working from home, so it will give me some time to actually get my work in order before I start Mat leave end of July.
To add we do live in the South West, it's a fairly small school (one class per year group) and we've had a pretty low transmission and death rate in the County. Our teacher in the bubble is fantastic and I think our child will get a lot of fun and social aspects to returning and will really help his mental health having a bit of normality and less gaming on our computer :-)